Refrigerating apparatus



Feb. 21, 1933." J. G. KING I REFRIGERATING APPARATUS Filed Dec. 30, 1930 INVENTOYR 3A4 ATI'ORNEYS Patented Feb. 21, 1933 UNITED STATES PATENT orncr.

JESSE KING, OF DAYTON, OHIO, ASSIGNOR TO FRIGDAIRE CORPORATION, OF DAYTON,

OHIO, A CORPORATION OF DELAWARE REFRIGERATING APPARATUS Application filed December 30, 1980. Serial No. 505,577.

This invention relates to refrigerating apparatus and more particularly to the flooded type of evaporator for cooling a brine tank. In the flooded type of evaporator-where certain refrigerants and lubricants 'are used, the lubricant floats upon the surface of the liquid refrigerant within the evaporator and often increases until the blanket of oil floatlng upon the surface of the liquid refrigerant has reached a considerable depth. This blanket ofoil retards the evaporation of liquid refrigerant within the evaporator 'since it causes a considerable difl'erential of pressure between the gaseous refrigerant above the blanket and the liquid refrigerant below the blanket. Consequently the compressor is called upon to do more work to keep the evaporator at the desired low temperature.

One of the objects of the invention is to decrease the differential in pressure between the gaseous refrigerant above the oil blanket and the liquid refrigerant below the oil blanket.

Another object of-theinvention is to-break up the oil blanket and to keep it in agitation. A still further object of the invention is to concentrate the gaseous refrigerant rislng from the lower portions of, the evaporator upon certain portions ofthe blanket of lubrlcant.

Further objects and advantages of the present invention will be apparent from the following description, reference being bad to the accompanying drawing, whereln a preferred form of the present invention is'clearly shown.

In the drawing: 7 Fig. 1 is a sectional view of the brine tank containing an evaporator embodying the invention, together with a diagrammatic representation of the remaining elements of a compression refrigerating system Fig.2 is a rear view of the evaporator; I 3 shows a fragmentary sectional view In Fig. 1 for illustrative purposes there is shown diagrammatically a compressor 21 for of the upperflportion of one of the headers,

compressing the refrigerant, preferably sulphur dioxide, and for forwarding it to the condenser 22 where it is liquefied and collected in the receiver 23. A supply conduit '26 supplies liquid refrigerant to the evaporator or cooling unit 27 where the liquid refrigerant vaporizes because of the absorption of heat from the brine in the brine tank 32 and this vaporized refrigerant is returned to the compressor through the return conduit 28. The actuating means for the compressor preferably comprises a motor 24 connected by pulle and belt means 25 to the compressor. pressure responsive switch means 29 is preferably connected to the return conduit 28 for controlling the motor 24 to provide alternating operating and idle periods of the compressor according to the pressure and consequently the temperature of the evaporator.

A large oval shape aperture is provided in the front Wall of the brine tank 32 and is covered by a face plate 31 which supports the front end of the supply reservoir or float chamber 30 of the evaporator 27. Connecting to the lower portion of the float chamber 30 at either end are pairs of headers 33 and 34 which support pairs of horizontal tubular refrigerant ducts 35 and 36 which form the main refrigerant ducts of the evaporator. a These ducts are provided witha plurality of vertical cross fins 37 which are provided with I flanged apertures 38 for. providing a good thermal bond between the refrigerant ducts and the fins and which are provided with curved flanges 39 at their upper ends for providing a good thermal contact between the float chamber and the upper portion of the fins. The refrigerant ducts 35 and 36 are also connected to the supply reservoir at their center portions by a pair of vertical tubes 40. These tubes extend through the upper pair. of refrigerant ducts 35 and are connected into the float chamber 30 at their upper ends and connected into the lower pair of refrigerant ducts 36 at their lower ends. The portion of the vertical tubes 40 within the pair of horizontal refrigerant ducts 35 are provided with apertures for .permitting the refrigerant to enter the vertical tubes 40 from the horizontal ducts 35. The entire assembly is dip-soldered to improve the thermal bond and to hold the parts together.

The level of liquid refrigerant within the supply reservoir 30 is maintained at a desired level 45 by a float arm which comprises the float ball 46 and a float arm 47 which operates the needle valve 48 to control the liquid refrigerant supplied through the conduit 26 according to the level of liquid refrigerant within the float chamber 30. When a refrigerant is used in which the lubricant is soluble andwhich is heavier than the lubricant, a blanket of lubricant 49 will float on the surface of the liquid refrigerant within the float chamber.

In Fig. 3 the detailed construction of the upper portion of one of the headers is shown. Each of the headers is provided with a bead 53 to reduce the amount of solder necessary to connect the header to the supplyreservoir 30. The upper portion of the header is provided with a. washer 50 having an orifice 51 therein forming a restricted opening. The horizontal refrigerant ducts 35 and 36 as well as the headers are kept flooded at all times with liquid refrigerant. Heat absorbed from the brine tank through the fins and the walls of the horizontal refrigerant ducts 35 and 36 causes liquid refrigerant therein to vaporize and form bubbles of gradually increasing size. Since there is little circulation within the horizontal refrigerant ducts and since the ducts are horizontal there is little force causing the bubbles collecting therein to move. The blanket of lubricant floating upon the liquid refrigerant within the float c amber also retards the movement of the bubbles within the horizontal refrigerant ducts 35 and 36 since it creates a pressure upon the surface of the liquid refrigerant. The bubbles forming in the horizontal refrigerant ducts 35 and 36 near the headers 33 and 34 growing larger, can escape more easily than those remote from a point of escape. These bubbles rising in the headers are forced to pass-through the orifice 51 in the washer 50 in their upward journey and because of this orifice their speed is increased and the bubbles pass upwardly in concentrated streams with sufficient velocity to break the blanket of lubricant and to start the circulation within the horizontal refrigerant ducts and to move the bubbles collected within the portion of the horizontal refrigerant ducts remote to the headers up and out of the headers to the orifice 51 so that they aid in keeping the blanket of lubricant in agitation and aid in causing the circulation within the horizontal refrigerant ducts 35 and 36.

In Fig. 4 a nozzle 52 is shown inserted in the upper portion of a header in place of the washer 50 with its orifice 51. This nozzle being more efiicient in changing the pressure ener of the bubbles into velocity energy and m concentrating the flow of the bubbles provides increased efiiciency in breaking the blanket of lubricant 49.

It will therefore be seen that applicant has provided an improved evaporator in which the blanket of lubricant is kept in a state of agitation and foams so that the lubricant is more readily withdrawn from the evaporator and returned to the compressor and so that the evaporator operates with a small differential of pressure between the gaseous refrigerant above the oil blanket and the liquid refrigerantbelow the oil blanket.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understod that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. An evaporator for refrigerating apparatus including a supply reservoir adapted to contain liquid refrigerant and a blanket of lubricant floating upon the liquid refrigerant, a refrigerant duct below the supply reservoir, means including a header connecting said refrigerant duct and said supply reservoir for concentrating the flow of gaseous refrigerant from the refrigerant duct to the supply reservoir for breaking the blanket of lubricant, and restricting means in the outlet of said header for increasing the velocity of the gaseous refrigerant discharged from the header.

2. An evaporator for refrigerating apparatus including a supply reservoir adapted to contain liquid refrigerant and a blanket of lubricant floating upon the liquid refrigerant, a refrigerant duct below the supply reservoir, means including a header connecting said refrigerant duct and said supply reservoir for concentrating the flow of gaseous refrigerant from the refrigerant duct to the supply reservoir for breaking the blanket of lubricant, and a restricted outlet in said header for increasing the velocity of the gaseous refrigerant discharged fromthe header.

3. An evaporator for refrigerating apparatus including a supply reservoir adapted to contain liquid refrigerant and a blanket of lubricant floating upon the liquid refrigerant, a refrigerant duct below the supply reservoir, means including a header connecting said refrigerant duct and said supply reservoir for concentrating the flow of gaseous refrigerant from the refrigerant duct to the supply reservoir for breaking the blanket of lubricant, and an orifice in the outlet of said header for increasing the velocity of the gaseous refrigerant discharged from the header.

4. An evaporator for refrigerating apparatus including a supply reservoir adapted to contain liquid refrigerant and a blanket of lubricant floating upon the liquid refrigerant, a refrigerant duct below the supply reservoir, means including a header connecting said refrigerant duct and said supply reservoir for concentrating the flow of gaseous refrigerant from the refrigerant duct to the supply reservoir forbreaking the blanket of lubricant, and an orifice in the outlet of header for increasing the velocity of the gaseous refrigerant discharged from the header.

5. An evaporator for refrigerating apparatus including a supply reservoir adapted to contain liquid refrigerant and ablanket-of lubricant floating upon the liquid refrigerant, a plurality of horizontal refrigerant ducts below the supply reservoir, a plurality of vertical cross fins bonded to therefrigerant ducts and the supply reservoir, means including a header at either end of the refrigerant ducts connecting the supply reservoir and the refrigerant ducts for concentrating the flow of gaseous refrigerant from the refrigerant ducts to the supply reservoir for breaking the blanket of lubricant and a re stricted outlet in said header for increasing the velocity of the gaseous refrigerant discharged from the header.

6. An evaporator for refrigerating apparatus including a supply reservoir adapted I to contain liquid refrigerant and a blanket of lubricant floating upon the liquid refrig erant, a plurality of horizontal refrigerant ducts below the supply reservoir, a plurality of vertical cross fins bondedto the refrigerant. ducts and the supply reservoir, means including a header at either end of the refrigerant ducts connecting the supply reservoir and the refrigerant ducts for concentrating the flow of gaseous refrigerant from the refrigerant ducts to the supply reservoir for breaking the blanket of lubricant, and a Venturi like orifice in the outlet of at least one of said headers for increasing the velocity of gaseous refrigerant discharged therefrom.

7. An evaporator for refrigerating apparatus including an elongated horizontally disposed supply reservoir adapted to contain liquid refrigerant and a blanket of lubricant floating upon the liquid refrigerant, a refrigerant duct below the supply reservoir extending horizontally and parallel to said supply reservoir, a header connecting said refrigerant duct and said supply reservoir below the lubricant contained in the reservoir for concentrating the flow of gaseous .refrigerant from the duct to the reservoir for breaking the blanket of lubricant, and restricting means in the outlet of said header for increasing the velocity of the gaseous refrigerant discharged from the header. I

8. An evaporator for refrigerating apparatus including a supply reservoir adapted to contain liquid refrigerant and a blanket of lubricant floating upon the liquid refrigerant, a refrigerant duct below the supply reser-voir, means including a header connecting said refrigerant duct and said supply reservoir for concentrating the flow of gaseous refrigerant from the duct to the reservoir for breaking the blanket of lubricant, and a Venturi like orifice in the outlet of said header for increas ing the velocity of the gaseous refrigerant discharged from the header.

9. ,An evaporator comprisin means providing a header for liquid refrigerant and lubricant, a plurality of ducts communicating with said header for receiving liquid re- JESSE G. KING.

CERTIFIC TE or CORRECTION.

Patent No. 1,898,548. 8 February 21, 1983.

JESSE 8. KING.

it is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 3, line 6, claim 4, for "an orifice" read "a nozzle"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 16th day of May, A. D. 1933.

. .9 Moore. (Seat) Acting Commissioner of Patents. 

